Genius 2 Computer

I have spent more time on this project than all other projects combined. As the name implies, the Genius 2 was the second computer I have designed and built. The first was a Z80 machine built in 1978. The Genius 2 computer was designed and built in 1983 and served me well until 1995.

I learned a lot about logic design and programming from this machine. Although it uses LSI microprocessors and memory chips, many of its subsystems were designed with TTL. I wrote all the software for the Genius 2 myself. There is not a byte of commercial software on this computer. Most of the software on the software pages originated here.

The Genius 2 specifications are (keeping in mind this is an early 1980s computer):

• 8 MHz 68000 processor
• 5 MHz Z80B processor
• 2 MBytes 41256 DRAM
• 1 KByte 2708 EPROM
• 1024 by 768 by 1 bpp bit-mapped graphics
• 14" monochrome monitor (modified NEC JB1410)
• 20 MByte hard disk (Seagate ST-225)
• 600 KByte 8" floppy disk (NEC FD1165)
• PC keyboard and mouse
• Parallel printer port (for Epson MX-100 printer)
• RS232 serial port (used by mouse)
• Cassette tape interface
• S-100 power supply with linear voltage regulators
• Perf board and wire wrap construction
• 350 integrated circuits (NMOS, LS-TTL, S-TTL)
• TTL subsystems for memory, graphics, hard/floppy disk controllers
• Software: total 110 K lines of code including operating system, editor, compiler, windows, and applications